Corrugated pipe hose assembly and connection method

ABSTRACT

The invention relates to corrugated pipe hose assemblies which are not provided with fixtures and which are used to transport preferably gaseous media in high-pressure applications, wherein a mount ( 3 ) is provided in order to receive an open end of the corrugated pipe ( 6 ) of the corrugated pipe assembly ( 2 ) and which is pressed therewith in order to form a metallic seal. The seal is obtained by means of a sealing bushing ( 25 ) between the inner wall ( 18 ) of one part ( 16 ) of the mount and the ribs ( 8 ) of the corrugated pipe ( 6 ). Another part ( 17 ) of the mount ( 3 ) firmly holds a section ( 27 ) of the covering ( 11 ) of the corrugated pipe hose assembly ( 2 ) in an axial direction and also with respect to tilting movements such that pivoting movements of the corrugated pipe hose assembly ( 2 ) do not result in a relative movement between the corrugated pipe ( 6 ) and the mount ( 3 ), especially with regard to one part ( 16 ). The sealing area thus remains unaffected even when mechanical load of the corrugated pipe hose assembly ( 1 ) occurs as a result of traction or bending.

The present invention relates to a corrugated pipe hose assembly and amethod for connecting a corrugated pipe hose, in order to create such acorrugated pipe hose assembly.

So-called corrugated pipe hoses are used as fluid conduits, inparticular for a movable connection of fluid-transporting aggregates.These assemblies comprise an inner corrugated pipe defining a fluidchannel. The corrugated pipe, which consists mostly of metal, isenclosed in a covering which essentially consists of plastic material,elastomer material, as well as other components. This coveringfrequently is composed of several layers. For example, it consists of ahose core or reinforcement which directly adjoins the corrugated pipe.In many cases, this hose core is provided with a so-called pressurecarrier, which consists of a coiled tension-resistant material to ensureresistance to pressure. In most cases, an additional hose cover isapplied to the pressure carrier to create an outer protective covering.During the manufacture of such corrugated pipe hoses, individual layersof the covering are extruded onto the corrugated pipe in consecutivesteps, which are provided with connection nipples on both ends. However,this limits the pipe length to production-related fixed, predetermineddimensions.

Therefore, the connection of corrugated pipe hoses, which do not haveconnection nipples, poses a particular problem. Also, users wish to beable to produce, on-site, i.e., independent of a predeterminedmanufacturing process, the desired connection assemblies from long orcontinuous semi-finished corrugated pipe hose material, without beingdependent on the special deliveries by a corrugated pipe hosemanufacturer.

The connection of a corrugated pipe hose with a continuing line or witha fluid-transporting aggregate must be mechanically stable. Thisconnection should provide a lasting seal and should be easy to produce.Neither pressure nor mechanical stresses, as are to be expected in theoperation of equipment and aggregates, should or may contribute toleakages or to any other damage of the connection.

If a corrugated pipe hose carries high pressures, ist such pressures areapplied at all times, and if the corrugated pipe hose is exposed totemperature changes, vibrations or any other long-term stresses, theconnection with a connection nipple can be particularly critical.

In view of this, the problem to be solved by the present invention is toprovide a possibility for manufacturing corrugated pipe hose assemblieswith the use of corrugated pipe hoses that have not been pre-fabricated,and display particular load-carrying ability.

This problem has been solved by the corrugated pipe hose assembly inaccordance with claim 1, as well as by the corresponding connectionmethod:

The inventive corrugated pipe hose assembly comprises a corrugated pipehose and at least one end mount, which is tightly connected with saidcorrugated pipe hose. This mount creates an attachment piece, which isconnected with a continuing line, for example, a pipe or a fluid channelof a connected aggregate. In order to connect the mount with thecorrugated pipe hose, an end section of the inner corrugated pipe of thecorrugated pipe hose is exposed and inserted in a first tubular part ofsaid mount. The fitting is deformed in such a manner that the inner wallof a sealing bushing fits tightly against at least one rib of thecorrugated pipe in order to create a seal. After being deformed, thepreferably initially cylindrical inner wall fits tightly against therib, so that this rib is pressed firmly against the inner wall.Furthermore, the material of the sealing bushing may protrude in aplastic or elastic manner into a space between the ribs. This press fitcreates a reliable seal, in particular, with respect to highlypressurized fluids such as, for example, CO₂. Such fluids areincreasingly being used as coolants in cooling devices, for example, inthe automobile industry. In addition, the tight fit of the corrugatedpipe in the first part of the mount—though mechanically buffered by thesealing bushing—effects a vibration-resistant mechanical assembly of thecorrugated pipe hose.

Closed ring-shaped spaces remaining between the rib interstices formbuffer spaces, which, depending on the diffusibility of the fluid,sooner or later fill with minute amounts of fluid and thus reduce thepressure differential at the respective sealing points. Sealing pointsare created, respectively, at the points of contact between a rib andthe sealing bushing.

The design of the sealing bushing may be completely homogenous. In sodoing, it is also possible to provide these sealing bushings withinserts, for example, to create diffusion barriers.

In addition, the mount is connected with the covering of the corrugatedpipe hose, for example, by a cupular element, into which the coveringprojects.

These types of connections can be created on a corrugated pipe hose endat a later time, namely, in that a part of the covering is removed andthe corrugated pipe end is secured in the mount.

In order to create the fluid-tight press fit of the corrugated pipe inthe first part of the mount, the tubular first part may be deformed inradial direction. This deformation must take place in a ring-shapedregion which extends over one or more ribs of the corrugated pipe. Thisdeformation may occur by means of a compression device comprisingseveral press jaws, which move in a radially inward direction and thuscause the tubular part to be narrowed in order to clamp the corrugatedpipe in place. By positioning and clamping the corrugated pipe onseveral ribs, a particularly secure mechanical connection and a goodseal are achieved. Optionally, magnetic compression or shrink fitting ispossible. The seal created by the sealing bushing may be supplemented bya metallic seal between the corrugated pipe and the mount part. To doso, a section of the mount having a smaller inner diameter is presseddirectly on the corrugated pipe. In particular at high pressures, thisincreases the diffusion resistance even more. Furthermore, the seal maybe enhanced and further improved by welding the joint. To do so, forexample, the mount part is first pressed together with the corrugatedpipe, and, subsequently, the press connection is heated. Heating may beachieved, for example, by means of an induction heating process. Awelded joint may form due to the combined action of the force of thepressure on the contact surface between the rib of the corrugated pipeand the inner wall, and due to the short-term high temperature action(i.e., below the melting point of the involved metals).

The first part of the mount may be connected to another fluid channel,for example, by means of a soldered or welded connection, i.e., byinserting an appropriate piece of the conduit in said part and bysoldering said part to said conduit. In addition, this conduit s may besoldered or welded to the corrugated pipe. An end section of thecorrugated pipe is preferably used for a soldered joint.

The second part of the mount may be in form-closed positive engagementwith the covering of the corrugated pipe hose. To do so, the second partmay be compressed radially inward, for example, by being pressedtogether with a narrower or wider ring-shaped section. If this pressureconnection is carried out in a narrow ring-shaped section, this sectionpreferably is located between two ribs of the corrugated pipe in orderto minimize or prevent a deformation of the corrugated pipe.

The second part of the mount may optionally be provided with a profileon its inside. To do so, the mount's walls may be provided with ribs oreven be threaded. As a result of this, a particularly firm connectionbetween the mount and the covering is achieved when these are pressedtogether.

Advantageous details of the embodiments of the invention result from thefollowing description of the figures, the drawings or the subclaims.

Examples of embodiment of the invention are illustrated by the drawings.They show:

FIG. 1 a detail of a corrugated pipe house assembly, in longitudinalsection;

FIG. 2 a detail of a corrugated pipe hose, in longitudinal section;

FIG. 3 a view of said corrugated pipe hose as in FIG. 2, with thecovering removed from the end section, in longitudinal section;

FIG. 4 a view of a mount for said corrugated pipe hose assembly as inFIG. 2, connected to another conduit means, in longitudinal section;

FIG. 5-7 modified embodiments of a corrugated pipe hose assembly inpressed-together state, viewed in longitudinal section.

FIG. 1 shows a detail of corrugated pipe hose assembly 1. Corrugatedpipe hose assembly 1 comprises a corrugated pipe hose 2, which forms aflexible fluid line. A mount 3 is used to connect corrugated pipe hose 2with a pipe piece 4 or another conduit means. Instead of pipe piece 4,it is possible to use any other connecting piece which forms acontinuing line or which is a component of a connected aggregate.Corrugated pipe hose assemblies of the type illustrated by FIG. 1 aresuitable for movable and vibration-resistant fluid connections betweenindividual aggregates or components of the cooling device. Specifically,the corrugated pipe hose assembly 1 is suitable for the connection offluid-containing spaces, which are subject to high internal pressures ofup to several hundred bars.

Corrugated pipe hose 2 contains a corrugated pipe 6. This corrugatedpipe 6 has a circular cross-section, in which case the diameter of thecorrugated pipe increases and decreases in an undulating manner alongits axis 7. Corrugated pipe 6 is a thin-walled metal pipe. As a resultof the undulating diameter variation, said pipe has ring-shaped,spaced-apart ribs 8 with interstices 9 between said ribs 8. Ribs 8 formindividual rings or a thread.

Corrugated pipe hose 2 is illustrated separately in FIG. 2. Corrugatedpipe 6 has a covering 11, which consists of a hose core 12, of apressure carrier 14 arranged concentrically with respect to corrugatedpipe 6 on hose core 12, and of an outer cover 15. Hose core 12, forexample, is an elastomer element, which is connected with corrugatedpipe 6 by positive material contact and is supported by ribs 8, andwhich fills interstices 9 between ribs 8. Its cylindrical outer coveringis enclosed by pressure carrier 14, which, for example, may be made of afabric hose, of cross-woven textile filaments or of wires, or asimilarly inelastic structure. The outer cover 15, in turn, consists ofan elastomer material or a plastic material, which is designed toprovide the outer protection of corrugated pipe hose 2.

Mount 3, which is shown by itself in FIG. 4, is used for the connectionof corrugated pipe hose 2. Mount 3 has a first tubular part 16 and asecond cupular part 17. Inner wall 18 of the first part 16 defines apassage opening 19. This opening is approximately cylindrical—at leastit has a cylindrical section 21 with a diameter that is slightly greaterthan the outer diameter of corrugated pipe 6.

The first part 16 extends into the bottom opening of the second part 17and is connected at this point with the base of the cupular second part17, for example, by being welded or soldered together or by beingdesigned in one piece. Extending from passage opening 19, which opensinto the cup, is a continuing opening 22 through part 17, so that mount3 is open at both its end sides. Wall 23 of the second part, whichdefines the opening, is configured, for example, cylindrically smooth.

Mount 3 comprises a sealing bushing 25, which is shown in FIG. 4 beforebeing connected and before pressing together mount 3 with corrugatedpipe hose 2. Sealing bushing 25 is configured as a hollow cylinder andhas a cylindrical inner wall 25 a. On its outside, said bushing has acylindrical generated surface. The outer diameter of sealing bushing 25corresponds approximately to, or is slightly smaller than, the innerdiameter of part 16. In contrast, the diameter of inner wall 25 a isslightly greater than the outer diameter of ribs 8 (FIG. 3). Sealingbushing 25 consists of a deformable material, for example, a plasticmaterial or an elastomer. Preferably, the material can be deformed in anelastic or plastic, or plastic/elastic manner. This material may be asilicone rubber, another rubber or any other suitable plastic materialwhich is not attacked by the fluid to be sealed in. The length ofsealing bushing 25 corresponds substantially to the length of part 16.It can be inserted in this part, in which case its end surface, in thetransition region between part 16 and pipe piece 4, abuts against anannular shoulder.

Corrugated pipe hose assembly 1 shown in FIG. 1 is manufactured asfollows:

First, a desired length of corrugated pipe hose 2 is cut from anappropriate pipe material. Then, in an end section 24 of corrugated pipe6, covering 11 is removed from corrugated pipe hose 2, a detail of whichis shown in FIG. 3. In so doing, end section 24 of corrugated pipe 6 isexposed. In so doing, at least a few ribs 8 of end section 14 arecleaned, for example, by means of rotating wire brushes to such anextent that said sections have a metallically clean surface on the outerperiphery of ribs 8. Potentially present elastomer residue from hosecore 12 needs not be removed from interstices 9; such residue may remainin the interstices. However, it may be advantageous to clear outinterstices 9 in order to create buffer spaces. In any case, theinterstices remain filled with the elastomer when ribs 8 form a thread,in order to close the thread between the ribs.

The transition between the exposed end section 24 of the corrugated pipeand the intact covering 11 is configured as an annular shoulder 27,which has a shape that is adapted to the shape of the base of cupularpart 17 (FIG. 1). In the present example of embodiment, annular shoulder27 is configured as a substantially plane ring-shaped end surface ofcovering 11.

For the continued assembly of mount 3, the prepared end of corrugatedpipe hose 2—as can be seen in FIG. 3—is inserted into the mount, as inFIG. 4, until the front end of corrugated pipe 6 abuts against pipepiece 4, and annular shoulder 27 abuts against the base of part 17. FIG.7 shows this state. In so doing, end section 24 is located in sealingbushing 25. Accordingly, end section 24 is seated with sealing bushing25 in part 16.

If required, a ring consisting of solder may be interposed betweencorrugated pipe 6 and the front end of pipe piece 4. Ribs 8 ofcorrugated pipe 6 are seated with slight play in sealing bushing 25.Sealing bushing 25 and covering 11 of corrugated pipe hose 2 are alsoseated with slight play in part 17 of mount 3.

If solder is present, a soldering step is now performed; in this case,the end of corrugated pipe 6 is soldered to pipe piece 4 or to part 16at soldering site 34. If a solder ring has previously been inserted,this soldering step involves heating the appropriate section of mount 3.In so doing, interstices 9 are not filled with solder; they remainempty. During this method step, if necessary, the soldered joint mayalso be provided between parts 16 and 17, unless this has been donepreviously. If, however, a soldered joint between the end of corrugatedpipe 6 and mount 3, or pipe piece 4, is not desired, the soldering stepmay be omitted.

In order to seal the fluid channel, i.e., ultimately seal corrugatedpipe 6 with respect to pipe piece 4, mount 3 is now converted into theshape shown in FIG. 1. To achieve this, each of the two mount parts(part 16, part 17) is squeezed radially inward in a ring-shaped area(for example, by several radially inward moving press jaws which act onthe circumference of part 16). Parts 16, 17 are deformed in a plasticmanner. Consequently, the free inner diameter of passage opening 19 isreduced in section 21. As a result, sealing bushing 25 is squeezed ontoend section 24 and its inner wall 25 a abuts—under radially inwardlydirected initial tension—against the ribs and against the elastomerresidue remaining in the interstices. This, and the press fit of sealingbushing 25 on inner wall 18 in part 16, produce a secure seal.

In section 28, ring-shaped radially inward-deformed press sections 29,31 are created, which, in axial direction, correspond to interstices 9between ribs 8, and which clamp covering 11 in place by form-closed andfrictional engagement. As a result of this, covering 11 of corrugatedpipe hose 2 is held firmly in mount 3 in axial direction. However, theseal is achieved by the metallic press fit between inner wall 18 and theperipheral surfaces of ribs 8 in section 21.

As shown by FIG. 1, corrugated pipe 6 may contain a hose or flexiblepipe 32, which projects—without play—into pipe piece 4 and covers ribs 8in the direction toward the fluid channel. This is possible inparticular because mount 3 connects the corrugated pipe hose withoutreducing the inner diameter of said hose at any point. Pipe 32 may beused to minimize noise developed by a fluid stream, as well as to reduceflow resistance. However, it may optionally be left out.

FIG. 5 shows a modified embodiment of mount 3. This mount correspondssubstantially to the above-described mount 3; the differences are asfollows:

The mount shown in FIG. 5 has, as a sealing means, not only a sealingbushing 25 but, in addition, a metallic seal. To achieve this, the firstpart 16 is divided such that it comprises a section 21 a having an innerdiameter, which corresponds approximately to, or slightly exceeds, theouter diameter of ribs 8; part 16 also comprises a second section 21 bhaving an inner diameter, which corresponds to the outer diameter ofsealing bushing 25. When pressed together, both sections 21 a, 21 b arepressed together in radially inward direction, as a result of which ametallic seal is created with respectively the outer apex of each rib 8in section 21 a. The compression of section 21 b causes bushing 25 to besqueezed in and, hence, an elastomer seal is created. In thisembodiment, interstices 9 are preferably emptied in order to createbuffer spaces 9 a. However, it is not necessary to empty interstices 9.

FIG. 6 shows another modified embodiment which largely corresponds tothe embodiment of FIG. 1. However, in addition to sealing bushing 25,another sealing bushing 26 located at a small axial distance fromsealing bushing 25 is provided. It is also possible for sealing bushings25, 26 to abut against each other end-to-end. This embodiment offers thepossibility of making sealing bushings 25, 26 of different materials.For example, different strength, elasticity or chemical resistanceproperties may exist. This embodiment offers the possibility of adaptingthe sealing array in an optimal manner even to difficult conditions.

Finally, FIG. 7 shows another modified embodiment of mount 3 and theseal that can be achieved therewith. Different from the embodiment as inFIG. 1, in this case, sealing bushing 25 is not designed in a homogenousmanner, instead it contains inserts 25 b, 25 c. These, as illustrated,may have the form of flat metal rings inserted coaxially in the bushingin order to create diffusion barriers and in order to limit the radialcompressibility of sealing bushing 25. Ring-shaped inserts 25 b, 25 care preferably located in the region of interstices 9. As shown, theseinserts may have a rectangular, square or even round cross-section. Inthis embodiment, the interstices are preferably cleaned out. However, itis also possible to omit the emptying step in the region of the inserts,in order to achieve a particularly high degree of compression betweenthe remaining elastomer residue and sealing bushing 25.

Other than that, the description of the embodiment of FIG. 1 appliesanalogously to that of the embodiments of FIG. 6 and FIG. 7.

Considering the modification of the above-described embodiments, sealingbushing 25 may feature, from the start, an allowance for part 16 and maybe pressed into said part. This bushing may also consist of a adhesivematerial that can be activated by deformation, or of a heat-fusiblematerial, or the like.

Considering the mount of the above-described embodiments, wall 23 ofpart 17 may be provided with a profile. This profile may consist ofindividual ring-shaped ribs, which are arranged concentric to axis 7. Inits original state, i.e., when part 17 has not been deformed yet, theinner diameter of ribs 33 is large enough that it exceeds the outerdiameter of cover 15. Consequently, section 28 of the covering caneasily be inserted in mount 3. During compression (radial compression ofpart 17), ribs 33 protrude into cover 15 of corrugated pipe hose 2 andsecure said corrugated pipe hose by creating a form-closed fit. Thisembodiment is of importance, in particular, when the radially inwardperipheral force for the deformation of part 17 is to be applied as aforce application in a relatively wide annular section of part 17, sothat almost the entire wall 23 can be deformed radially inward. Insteadof ribs 33, a tapping screw thread may be provided, which cuts intocover 15 when mount 3 is screwed to corrugated pipe hose 2.

For the connection of corrugated pipe hoses, which are not provided withfittings and are designed preferably for the transport of gaseous mediain high-pressure applications, a mount 3 is provided, which receives anexposed end of corrugated pipe 6 of corrugated pipe hose 2 and ispressed together with said hose in order to create a metallic seal. Thisseal is achieved by a sealing bushing 25 located between inner wall 18of part 16 of the mount and ribs 8 of corrugated pipe 6. Another part 17of mount 3 holds a section 28 of covering 11 of corrugated pipe hose 2in axial direction and also with respect to tilting movements, such thatthe pivoting movements of corrugated pipe hose 2 do not result in arelative movement between corrugated pipe 6 and mount 3, specificallywith regard to part 16. Thus, the sealing area remains unaffected, evenwhen mechanical traction or bending stresses act on corrugated pipe hoseassembly 1.

1. A corrugated pipe hose assembly for pressurized devices comprising: acorrugated pipe hose comprising a corrugated pipe, which has a pluralityof helical or ring-shaped ribs arranged axially at a distance from eachother, and which is enclosed by a covering, which encloses thecorrugated pipe with the exception of at least one end section; a mount,which has a first tubular part with a passage opening for receiving theend section and a second tubular part with an opening for receiving asection of covering, in which case the passage opening is defined by aninner wall of the first part and the opening is defined by a wall of thesecond part; a conduit means, which is connected with the mount in afluid-tight manner; and at least one sealing bushing having an innercylindrical wall and located in the first tubular part, the innercylindrical wall disposed in a press fit with the plurality of ribs ofthe corrugated pipe hose and the inner wall of the first tubular partsuch that the ribs of the corrugated pipe hose do not directly contactthe first tubular part, wherein the at least one sealing bushing iselastically deformed by deforming the first tubular part of the mount.2. The corrugated pipe hose assembly as in claim 1, characterized inthat the tubular part is a metal pipe which is deformed in its radialdirection such that the sealing bushing abuts, in a sealing manner,between its inner wall and the plurality of ribs of the corrugated pipe,in which case a fluid-tight press fit is created between the first partand the corrugated pipe.
 3. Corrugated pipe hose assembly as in claim 1,characterized in that the first tubular part (16) is deformed in itsradial direction such that it presses the inner wall (25 a) of thesealing bushing (25) against several ribs (8) of the corrugated pipe (6)in order to create a seal, and that, between the first part (16) and thecorrugated pipe (6), with the sealing bushing (25) being interposed, afluid-tight press fit is created.
 4. The corrugated pipe hose assemblyas in claim 1, characterized in that the first part can be plasticallydeformed.
 5. The corrugated pipe hose assembly as in claim 4,characterized in that the plastic deformation in a ring-shaped sectionof the first part is directed radially inward.
 6. The corrugated pipehose assembly as in claim 1, characterized in that the mounted sealingbushing can be plastically deformed.
 7. The corrugated pipe hoseassembly as in claim 1, characterized in that the deformed sealingbushing creates a form-closed connection between the corrugated pipe andthe deformed first part.
 8. The corrugated pipe hose assembly as inclaim 1, characterized in that the sealing bushing is made of a singlematerial.
 9. Corrugated pipe hose assembly as in claim 1, characterizedin that the sealing bushing (25) comprises at least one insert (25 b) ofa different material.
 10. Corrugated pipe hose assembly as in claim 9,characterized in that the conduit means (4) is soldered to the firstpart (16) and to the corrugated pipe (6).
 11. Corrugated pipe hoseassembly as in claim 1, characterized in that the sealing bushing (25)is associated with another sealing bushing (26) which, in axialdirection, adjoins the sealing bushing (25) or is arranged at a distancefrom said bushing (25).
 12. The corrugated pipe hose assembly as inclaim 1, characterized in that the corrugated pipe is connected with aconduit means.
 13. The corrugated pipe hose assembly as in claim 1,characterized in that the first part and the second part are joined bywelding or soldering, or are connected in one piece.
 14. The corrugatedpipe hose assembly as in claim 1, characterized in that the second partis in form-closed engagement with covering.
 15. The corrugated pipe hoseassembly as in claim 1, characterized in that the second part is pressedtogether with the covering.
 16. The corrugated pipe hose assembly as inclaim 1, characterized in that the second part is provided with an innerprofile.
 17. The corrugated pipe hose assembly as in claim 1,characterized in that the corrugated pipe contains a hose.